'It's only a blood test': what people know and think about venepuncture and blood.

Medicine finds human blood infinitely useful. It is a source of important and sometimes controversial information about individuals, their relatives and the general public. Blood also has economic value, carries a heavy cultural freight, and can transmit dangerous diseases. Yet there is precious little sociological analysis of how these radically different applications, potentials and significations are managed in health care settings where, it is no exaggeration to claim, everyday a vast quantity of blood is produced by venepuncture. This paper focuses on blood produced in hospitals for tests. The data were derived from 19 focus groups of patients, health care professionals, and members of the public, held between 2002 and 2003, in and around the obstetrics and gynaecology department of a large London teaching hospital. Not surprisingly, all the participants had had a blood test at some time or other. Yet their responses suggest no template exists for talking about them. No-one--lay or professional--had a full picture of how blood produced for tests circulates around the hospital. Lay people tended to envisage it as remaining in a liquid form whereas health care professionals saw it as materially and substantially transformed. Participants deployed a variety of ritual and rhetorical devices that devalue blood produced for tests. Nonetheless, blood left over from tests emerged as a significant anomaly, simultaneously an excess (waste), a challenge (to use wisely), or a potential crime (illegitimate research).